346 CLASS MAMMALIA. 



point, to the projection formed between the eye-brows, or 

 over the root of the nose, by the frontal line. 



" The angle intercepted between these two lines is the 

 facial angle. 



jp - ' Take with a compass the distance 



between the two auricular foramina. 

 ,3 Carry it to o, o. Take the distance 

 from one of the auricular foramina to 

 "o" the middleof theedge of the incisives : 



make with this distance o, d, the isosceles triangle 0,0, d ; 

 take in like manner the distance between the auricular 

 foramen and the projection of the forehead, and make the 

 triangle 0, o,f. 



tC Take the distance d, ff, between the edge of the inci- 

 sives and this same projection, with g,f, and d,ff, make on 

 g, d, the triangle g, d, ff, the angle g, d, ff, will be the 

 facial angle. 



" If this operation be once performed for a species in 

 each genus, no future mistake can ensue, and a simple 

 glance will be sufficient to distinguish them. 



" It is principally the facial angle which we use to dis- 

 tinguish our genera. 



" We consider also the palatine angle which is formed 

 bv the meeting of the horizontal line with another line 

 supposed to divide into two equal parts the plane of the 

 alveolar arcade, and which we name the palatine line. 

 When these two last lines are parallel, which is often the 

 case, the palatine angle is 0. 



" In applying these measures to the crania of different 

 quadrumana, we have obtained the following results : 



" The Orang-Outang of Camper, the Jocko and the 

 Gibbon of Buffon had the facial angle from 56° to 63°. 

 The Sapajous, and the Sagoins of Buffon, with the excep- 

 tion of the Alouatta, have this angle about 60°. The Gue- 

 nons or Cercopitheci have it 50 and a few degrees. The 



